Antibiotics and oral contraceptive failure - a case-crossover study

Background: Evidence on the association between antibiotic use and combined oral contraceptive (COC) failure is controversial. We examined the effect of concomitant antibiotic treatment on the risk of breakthrough pregnancy among COC users. Study Designs: We performed a case-crossover study of 1330 COC failure cases among 17,721 women from the Slone Epidemiology Center Birth Defects Study (1997-2008) and among 25,941 women from the National Birth Defects Prevention Study (NBDPS, 1997-2005). Self-matched odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by comparing antibiotic use between the 4 weeks before conception ("case period") and the 4-8 weeks before conception ("control period") using conditional logistic regression. A case time-control analysis was conducted using nonusers of COCs with unplanned pregnancies as controls. Results: For the combined data, the self-matched OR was 1.08 (95% CI: 0.63-1.84) and the case time-control OR was 1.12 (0.63-1.98) for antibiotics overall. The results did not appreciably differ when adjusted for characteristics that might vary between the case and control period. However, among COC failure cases from the NBDPS, allowing a 1-month gap between the case and control period resulted in a self-matched OR of 1.45 (0.85-2.50) and a case time-control OR of 1.55 (0.86-2.79) for antibiotics overall. Conclusions: We did not find an association between concomitant antibiotic use and the risk of breakthrough pregnancy among COC users. However, due to limited power and potential carryover effects, findings from this study cannot rule out an elevated risk of COC failure among antibiotic users. (C) 2011 Elsevier Inc. All rights reserved

Maternal Exposure to Criteria Air Pollutants and Congenital Heart Defects in Offspring: Results from the National Birth Defects Prevention Study

Background: Epidemiologic literature suggests that exposure to air pollutants is associated with fetal development

The national birth defects prevention study: A review of the methods: NBDPS METHODS REVIEW

The National Birth Defects Prevention Study (NBDPS) is a large population-based multi-center case-control study of major birth defects in the United States

Antiherpetic Medication Use and the Risk of Gastroschisis: Findings From the National Birth Defects Prevention Study, 1997-2007

Background: Previous studies examining the teratogenic effects of antiherpetic medications have found no associations for birth defects overall but have not examined the risk of specific birth defects. Methods: The National Birth Defects Prevention Study ascertains population-based cases with birth defects and live-born controls without birth defects in 10 states across the United States for the purpose of identifying potential teratogenic risk factors. Mothers of cases and controls are interviewed within 2 years of their estimated date of delivery about demographic, medical and behavioural factors before and during pregnancy. This analysis examined the possible association between use of antiherpetic medications (acyclovir, valacyclovir or famciclovir) during early pregnancy and gastroschisis, a birth defect of the abdominal wall. Results: The mothers of 1.1% (n = 10) of 941 gastroschisis cases and 0.3% (n = 27) of 8339 controls reported antiherpetic medication use during the month before conception through the third month of pregnancy. The adjusted odds ratios for such use in relation to gastroschisis were 4.7 [95% confidence interval 1.7, 13.3] and 4.7 [95% CI 1.2, 19.0] among women with and without self-reported genital herpes, respectively, when compared with women without antiherpetic use or herpes. Among women reporting no antiherpetic medication use, the odds ratio for self-reported genital herpes in relation to gastroschisis was 3.0 [95% CI 1.6, 5.7]. Conclusions: Our study raises the possibility of an increased risk of gastroschisis because of either antiherpetic medication use during early pregnancy or the underlying genital herpes infection for which it was indicated

Use of Antiepileptic Medications in Pregnancy in Relation to Risks of Birth Defects

Purpose: To evaluate use of specific antiepileptic drugs (AEDs) in pregnancy in relation to specific birth defects. Methods: Using data from the National Birth Defects Prevention Study, we assessed use of AEDs and the risk of neural tube defects (NTDs), oral clefts (OCs), heart defects (HDs), hypospadias, and other major birth defects, taking specific agent, timing, and indication into consideration. Results: Drug-specific increased risks were observed for valproic acid in relation to NTDs [adjusted odds ratio (aOR), 9.7;, 95% confidence interval (CI), 3.4-27.5], OCs (aOR, 4.4; 95% CI, 1.6-12.2), HDs (aOR, 2.0; 95% CI, 0.78-5.3), and hypospadias (aOR. 2.4; 95% CI, 0.62-9.0), and for carbamazapine in relation to NTDs (aOR, 5.0; 95% CI, 1.9-12.7). Epilepsy history without AED use did not seem to increase risk. Conclusions: Valproic acid, which current guidelines suggest should be avoided in pregnancy, was most notable in terms of strength and breadth of its associations. Carbamazapine was associated with NTDs, even after controlling for folic acid use. Sample sizes were still too small to adequately assess risks of less commonly used AEDs, but our findings support further study to identify lower risk options for pregnant women

Status of Population‐based Birth Defects Surveillance Programs before and after the Zika Public Health Response in the United States

Background: The 2016 Zika public health response in the United States highlighted the need for birth defect surveillance (BDS) programs to collect population‐based data on birth defects potentially related to Zika as rapidly as possible through enhanced case ascertainment and reporting. The National Birth Defects Prevention Network (NBDPN) assessed BDS program activities in the United States before and after the Zika response. Methods: The NBDPN surveyed 54 BDS programs regarding activities before and after the Zika response, lessons learned, and programmatic needs. Follow‐up emails were sent and phone calls were held for programs with incomplete or no response to the online survey. Survey data were cleaned and tallied, and responses to open‐ended questions were placed into best‐fit categories. Results: A 100% response rate was achieved. Of the 54 programs surveyed, 42 reported participation in the Zika public health response that included BDS activities. Programs faced challenges in expanding their surveillance effort given the response requirements but reported mitigating factors such as establishing and enhancing partnerships and program experience with surveillance and clinical activities. Beyond funding, reported program needs included training, surveillance tools/resources, and availability of clinical experts. Conclusions: Existing BDS programs with experience implementing active case‐finding and case verification were able to adapt their surveillance efforts rapidly to collect and report data necessary for the Zika response. Program sustainability for BDS remains challenging; thus, continued support, training, and resource development are important to ensure that the infrastructure built during the Zika response is available for the next public health response